Award Date
12-15-2025
Degree Type
Thesis
Degree Name
Master of Science (MS)
Department
Life Sciences
First Committee Member
Matthew Meiselman
Second Committee Member
Andrew Andres
Third Committee Member
Allen Gibbs
Fourth Committee Member
Mo Weng
Fifth Committee Member
Louisa Messenger
Number of Pages
84
Abstract
Arthropods are uniquely susceptible to environmental challenges. They are ectothermic, often small, and have a high surface-area-to-volume ratio, making them particularly vulnerable to environmental fluctuations. As a result, they are critically dependent on adaptive responses to the environment for survival, and so studying them therefore provides a unique opportunity to investigate basal adaptive mechanisms that may be highly conserved across animal species.
This thesis investigates the physiological and behavioral responses of Ixodes scapularis and Drosophila melanogaster to environmental conditions, respectively, light and temperature
In Ixodes, we examined circadian regulation of locomotion and arousability. Our findings indicate that ticks exhibit heightened activity and arousability during the night, suggesting a nocturnal behavioral pattern. Diurnal quiescence meets the classical definition of sleep. Nighttime wakefulness may enhance their ability to locate hosts during periods of increased host activity.
In Drosophila, we explored the mechanisms underlying reduced egg production at extreme temperatures. Utilizing a heat-sensitive ion channel (TRPA1) to activate Gal4 lines, we identified neuronal circuits that mediate metabolic suppression in response to cold. Further, RNA interference screening of thermosensitive ion channels revealed that pan-neuronal silencing of genes including Painless and TRPA1 increases egg production under heat stress, implicating these channels in physiological response to temperature. Investigations into Johnston's organ, a mechanosensory structure, suggested its involvement in regulation of reproduction.
Collectively, these studies provide insights into the adaptive mechanisms of ectothermic organisms in response to environmental conditions, displaying that for optimal success, animals must tightly control when and where energy is utilized.
Keywords
Dormancy; Drosophila; Ixodes; Sleep; Temperature
Disciplines
Animal Sciences | Biology | Life Sciences
File Format
File Size
6000 KB
Degree Grantor
University of Nevada, Las Vegas
Language
English
Repository Citation
Marshall, Jack, "Sleep and Dormancy: Strategies of Ectothermic Arthropods to Optimize Energy Usage in Dynamic Environments" (2025). UNLV Theses, Dissertations, Professional Papers, and Capstones. 5447.
https://oasis.library.unlv.edu/thesesdissertations/5447
Rights
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